I'm not as salty as some dogs so add a little salt to the below BUT here's a take, already tweaked once:
The location looks like it could be a really great sounding spot. I suspect the repair guy wasn't overstressing about compliance matching given the spider is also ancient. Try them out and if you're not happy a full recone is still an option. The suspension compliance isn't going to make a ton of difference unless you start trying to do tuned alignments. An infinite baffle makes most functional differences here pretty minimal in practice.
I'm not saying I wouldn't prefer a full recone and remag, I certainly would. But, don't let the perfect be the enemy of the good here. A full recone/remag was always the only way to truly get them back on-spec, the local guy probably can't re-mag 'em. You'll certainly want to measure and see how closely they match, if they're just a little different Fs/Qms/Qts/Vas from spec (Say +/-25%) but pretty close to each other (+/- 10%), you are actually probably in pretty darned good shape given the reasonable investment thus far. EQ is your friend and it's becoming more available all the time (there are parametric EQs in the WiiM Ultra streamer for ex).
The location looks like it could be a really great sounding spot. I suspect the repair guy wasn't overstressing about compliance matching given the spider is also ancient. Try them out and if you're not happy a full recone is still an option. The suspension compliance isn't going to make a ton of difference unless you start trying to do tuned alignments. An infinite baffle makes most functional differences here pretty minimal in practice.
I'm not saying I wouldn't prefer a full recone and remag, I certainly would. But, don't let the perfect be the enemy of the good here. A full recone/remag was always the only way to truly get them back on-spec, the local guy probably can't re-mag 'em. You'll certainly want to measure and see how closely they match, if they're just a little different Fs/Qms/Qts/Vas from spec (Say +/-25%) but pretty close to each other (+/- 10%), you are actually probably in pretty darned good shape given the reasonable investment thus far. EQ is your friend and it's becoming more available all the time (there are parametric EQs in the WiiM Ultra streamer for ex).
Don’t know where you are, but I think Santon in Toronto can remag them
and install a GPA cone kit if you source them .
Your cabinet is sealed so the new surround really won’t affect the LF response that much. The GPA cone probably isn’t the same as the Altec and Altec made them for 30/40 years in different variations. Frankly I think the new edges you have are fine, give them 100 hours of some reasonable volume,
your call if you want to spend the money going further, but is there audio benefits to it? .
and install a GPA cone kit if you source them .
Your cabinet is sealed so the new surround really won’t affect the LF response that much. The GPA cone probably isn’t the same as the Altec and Altec made them for 30/40 years in different variations. Frankly I think the new edges you have are fine, give them 100 hours of some reasonable volume,
your call if you want to spend the money going further, but is there audio benefits to it? .
Thanks for all the feedback. GPA hasn't responded to the messages I sent via contact form on their webpage, so I called them today. I got an answering machine with a very generic message saying I had reached the number I called, which is the number on their website. No company name or any other information. Seemed a bit strange and didn't leave me with a good first impression, but we'll see if I get a call back.
I'll keep Stanton in mind, but GPA doesn't sell parts now. So I'd have to source a recone kit from someone else if I decide to go that route. I have been listening to the speakers in the temporary baffles and they're sounding pretty good, so I think I'm going to live with them for awhile. I still need to finish the living room floors, build proper speaker baffles, and address room treatments like curtains, area rug, etc. Not to mention new or recapped crossovers. Those things will eat up my modest budget pretty quickly and will likely have a greater impact on the sound quality than a recone kit. I also bought an old Scott LK-72B tube amp on the weekend that needs some upgrades, so that's going to cost a few bucks too.
I'll keep Stanton in mind, but GPA doesn't sell parts now. So I'd have to source a recone kit from someone else if I decide to go that route. I have been listening to the speakers in the temporary baffles and they're sounding pretty good, so I think I'm going to live with them for awhile. I still need to finish the living room floors, build proper speaker baffles, and address room treatments like curtains, area rug, etc. Not to mention new or recapped crossovers. Those things will eat up my modest budget pretty quickly and will likely have a greater impact on the sound quality than a recone kit. I also bought an old Scott LK-72B tube amp on the weekend that needs some upgrades, so that's going to cost a few bucks too.
Santon have access to all the recone parts if you go that way. Yes theres more to be had recapping the crossovers.
there are redesigned crossovers as well. if you stick with the stock crossover get a really good cap for the 3uf . The 14uf would be a couple of caps in parrallel. Depends what fits in the crossover case and budget.
there are redesigned crossovers as well. if you stick with the stock crossover get a really good cap for the 3uf . The 14uf would be a couple of caps in parrallel. Depends what fits in the crossover case and budget.
Thanks for the schematic. I don't think I've come across that one before. I've read some posts where people say the factory crossovers are not worth upgrading, but I'm not sure if that's true. I was looking into the parts for the Markwart crossover, which seems to be highly recommended. However, when I started pricing the higher end components that most people are using, like audiophile or NOS motor run capacitors, they started to get pretty expensive. So I started looking into lower cost parts like Dayton caps from Parts-Express, but I don't think I've come across any examples of people using those parts yet. So not sure it's a good idea.
Here's a screen shot of the part list I put together if you have any feedback. I think it's still missing a couple parts like L-Pads. By the way, I've been listening to the speakers a lot and they are sounding great. Bass definitely isn't a problem. It might be a bit too boomy right now, but I think that can be addressed with thicker baffles, bracing, damping, furniture in room etc. The highs can be fatiguing with my SS Yamaha amp, but they sound smoother with the Scott tube amp.
Here's a screen shot of the part list I put together if you have any feedback. I think it's still missing a couple parts like L-Pads. By the way, I've been listening to the speakers a lot and they are sounding great. Bass definitely isn't a problem. It might be a bit too boomy right now, but I think that can be addressed with thicker baffles, bracing, damping, furniture in room etc. The highs can be fatiguing with my SS Yamaha amp, but they sound smoother with the Scott tube amp.
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@streetcore
Ticknpop isn't doing you any favours by posting the schematic for the 604E duplex ( which is a 12-16 ohm model ) while your 604-8G's have 8 ohm voice-coils.
IOW, don't use the N1500 schematic for your 8G's .
Jeff Markwart published an updated 8G network that's worth sourcing ( the values for the 8G are in Note #6 ).
🙂
Ticknpop isn't doing you any favours by posting the schematic for the 604E duplex ( which is a 12-16 ohm model ) while your 604-8G's have 8 ohm voice-coils.
IOW, don't use the N1500 schematic for your 8G's .
Jeff Markwart published an updated 8G network that's worth sourcing ( the values for the 8G are in Note #6 ).
🙂
Thanks EarlK. I noticed the other schematic was for the 604E. Didn't know the impedance was different, but would have done more homework if I decided to go that route. I have the Markwart schematic and the parts in the shopping cart I shared are based on his notes for the 604-8G.
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I'm going to give you a tip on how high your 604 should sit, after a lot of tests, I and my comrades who have 604 in different versions have experienced that approx. 83 cm from the floor to the top of the horn is what delivers the most homogeneous sound image, to have them at ear level they sound good but don't have the same balance.
But don't take my advice as absolute truth, but the three of us were surprised that there was such a difference of 7-8 cm from ear height.
Good luck with your build and hope they turn out the way you envisioned.
But don't take my advice as absolute truth, but the three of us were surprised that there was such a difference of 7-8 cm from ear height.
Good luck with your build and hope they turn out the way you envisioned.
Thanks for your advice about speaker height. The top of the horns are currently about 86cm from the floor in my temporary baffles. I was worried that was too low, but couldn't go higher due to the built-in cabinet restrictions. I actually wanted to lower them to make room for a frame that will hold the grill cloth, but was worried they would be too low. So it's great to hear it may be beneficial to drop them a few more centimetres.
In your testing did you keep the speakers perpendicular to the floor, or did you tilt speakers back at all?
In your testing did you keep the speakers perpendicular to the floor, or did you tilt speakers back at all?
@streetcore
Hi,
You might not be aware of these buying choices up here in Canada ( > since you chose to display a P.E. cart ).
Dayton Polypropylene Caps at SOLEN
Dayton Motor-Run Caps from GRAINGER
I prefer the extra damping of "wet" MPP style caps > so the Dayton's from Granger would be my starting choice ( over the "dry" Daytons ).
SOLEN 16 AWG Inductors
SOLEN 20 AWG Inductors
- These inductor sizes keep their DCR at less than 10% of the drivers DCR's > so, I would start off with these coil sizes.
If you're keen to spend more $$ on better known MKP in Oil ( Motor-Runs ), Sayal Electronics has a small collection of Motor-Runs.
Their choices that start with the Prefix "Z" should be older//surplus Aerovox motor-runs ( since Google will return Sayal's item numbers as an Aerovox type >> while the others appear to come from NTE Electronics ).
🙂
Hi,
You might not be aware of these buying choices up here in Canada ( > since you chose to display a P.E. cart ).
Dayton Polypropylene Caps at SOLEN
Dayton Motor-Run Caps from GRAINGER
I prefer the extra damping of "wet" MPP style caps > so the Dayton's from Granger would be my starting choice ( over the "dry" Daytons ).
SOLEN 16 AWG Inductors
SOLEN 20 AWG Inductors
- These inductor sizes keep their DCR at less than 10% of the drivers DCR's > so, I would start off with these coil sizes.
If you're keen to spend more $$ on better known MKP in Oil ( Motor-Runs ), Sayal Electronics has a small collection of Motor-Runs.
Their choices that start with the Prefix "Z" should be older//surplus Aerovox motor-runs ( since Google will return Sayal's item numbers as an Aerovox type >> while the others appear to come from NTE Electronics ).
🙂
Thanks EarlK! I did look at Grainger and have bought stuff from them before. For some reason, I thought their motor run caps were much more expensive than the Dayton caps at PE, but I just looked again and they would only be about $20 more (about $56CAD vs $35CAD for the lot). I was using PE mostly because they seemed to have just about everything I would need and I was trying to avoid multiple shipping charges. I also live on the border and could get free shipping to a depot over there.
I looked at Solen before too, but wasn't really sure what I was looking for and didn't know about "wet" vs "dry" Daytons. Their PMPC Daytons would be the most expensive at about $110CAD for the lot. Like I said, I'm trying to keep costs down, so the ones from Grainger sound like a good choice and I can pickup at my local store and save on shipping.
I looked at the Solen inductors too, but the Markwart schematic specifies "Copper Foil Air Core". That's why I choose the ones at PE. Would the Solen ones be a good subsitute, even though they are not Foil?
I looked at Solen before too, but wasn't really sure what I was looking for and didn't know about "wet" vs "dry" Daytons. Their PMPC Daytons would be the most expensive at about $110CAD for the lot. Like I said, I'm trying to keep costs down, so the ones from Grainger sound like a good choice and I can pickup at my local store and save on shipping.
I looked at the Solen inductors too, but the Markwart schematic specifies "Copper Foil Air Core". That's why I choose the ones at PE. Would the Solen ones be a good subsitute, even though they are not Foil?
Since I Bi-amp the bass frequencies in my setup ( but use Passive LC Hi-Passing on the horns ) > I don't have much of a relevant opinion on the differences one might expect to hear in the bass frequencies between using those two type of coils.
I know that I've read diametrically opposed opinions for both types of coils ( & from people I've come to respect through their posting life-experiences ).
Free Shipping is always good >> so I get where you are coming from.
International shipping rates ( from the US up to Canada ) can be a real deal-breaker ( IME ).
Here's another ( US based ) supplier of MKP in Oil Motor-Runs that I've used in the past that has great pricing ( on quality brands ). Surplus Center Motor Runs
-Pretty limited choices though for your project.
🙂
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Look at the Axon caps at Parts Connexion.
2.4 uf + .68uf = 3.08.
Altec was +/- 10 %
( even better is 3 x .82 uf + 0.56uf ) because Film/ foil is better at high current - but higher cost and larger- but a good deal for film/foil caps
2.4 uf + .68uf = 3.08.
Altec was +/- 10 %
( even better is 3 x .82 uf + 0.56uf ) because Film/ foil is better at high current - but higher cost and larger- but a good deal for film/foil caps
No, they don't tilt back is the simple answer, I don't even have them toe in. Carl one of my hifi friends with 604E he chose 82 cm and he is happy with it.
It's been slow going, but I've been making some progess on my built-ins. I'm the kind of guy who needs to test lots of ideas before commiting to a design or materials. So I've been making sketches, drawings, cardboard cut-outs, and prototypes out of scrap wood. The picture below shows where I'm at now and I think I may be happy with this design. The final outer frame will be a bit more elaborate with a traditional cope and stick construction similar to cabinet doors or a window sash. I've also ordered some samples of Guilford of Maine FR701 fabric for the grills. With such large grills, the correct fabric will obviously be crucial to making this project aesthetically pleasing.
I've also taken some inspiration from the book GM posted a while back. It has a section about infinite baffles that includes the images below of a large two-way system built into a fireplace. I like the idea of putting the baffle on hinges so I have easier access to connect wires or make alterations inside the cabinets.
Another question I've been contemplating is insulation inside the cabinets. I've read that cotton or recycled denim would be best, but it seems to be very difficult to find, expecially here in Canada. Would Rockwool or regular pink fiberglass insulation be acceptable to start?
Thanks.
I've also taken some inspiration from the book GM posted a while back. It has a section about infinite baffles that includes the images below of a large two-way system built into a fireplace. I like the idea of putting the baffle on hinges so I have easier access to connect wires or make alterations inside the cabinets.
Another question I've been contemplating is insulation inside the cabinets. I've read that cotton or recycled denim would be best, but it seems to be very difficult to find, expecially here in Canada. Would Rockwool or regular pink fiberglass insulation be acceptable to start?
Thanks.
Would Rockwool or regular pink fiberglass insulation be acceptable to start?
I use (10-12cm) rockwool behind the speaker in my case it will be 58cm wide 70cm high, the rest of the walls I have fixed cover which you use and protect furniture when they are moved they are mostly used to dampen reflections in the box.
I use (10-12cm) rockwool behind the speaker in my case it will be 58cm wide 70cm high, the rest of the walls I have fixed cover which you use and protect furniture when they are moved they are mostly used to dampen reflections in the box.
It looks really nice- but I'd think about some thick wool felt on the back of the grille frame, to damp any cavity resonances and the frame itself. You don't want little resonating pockets of air in front of the driver. Good call prioritizing the build and XOs.
Thanks for the compliment and the advice. How much felt are you suggesting? Should I cover the entire back of the grill, except for the area directly in front of the speaker?
I'd want to basically have the felt compressed between the speaker mounting baffle and the entire backside of the grille, to keep the wood "damped" so the grill frame itself doesn't vibrate (the altecs can move some air!). You could use foam or another gasket solution, felt is nice because it's not sticky and is a little porous and absorbent, f11/f13 wool felt is preferred but not required. You seem to be handy enough to manage a good solution, the real goals are to prevent the grille itself from singing along with the music too much, and to prevent any cavity resonances in the spaces between the baffle and grille frame, you can use a less acoustically absorbent solution or other alternatives if you can "fill in" those gaps and keep the baffle from being too free to vibrate. .